Rubber tip for lead-pencils.



Wizeumsw PATENTED AUG. 13, 1907.

F. MOINTYRE.

RUBBER TIP FOR LEAD PENGILS.

APPLIOATION FILED JUNE 13. 1907.

- section of the same.

FRANK MeINTYRE, OF NEW YORK,

N. Y., ASSIGNOR TO EAGLE PENCIL COMPANY, OF NEW YORK, N. Y.

RUBBER TIP FOR LEAD-PENCILS.

Specification of Letters Patent.

Patented Aug. 13, 1907.

. A plication filed June 18,1907. Serial No. 378,832.

To all whom it may concern:

Be it known that I, Fmnx MCINTYRE, of the city, county, and State of NewYork, have invented a new and useful Improvement in Rubber Tips forLead- Pencils, of which the following is a specification.

The characteristic of my improved tip is that the rubber or erasivematerial is in the shape of a ball, and that this ball is contained in asocket, having slightly more than hemispherical dimensions, and closedupon the ball to such an extent as to prevent the escape of the ball butnot to prevent it from turning in its socket, so as to permit it topresent new rubbing or erasive surfaces-the wear being in this waydistributed over the whole surface of the ball.

H In the accompanying drawing to which I shall now refer for a betterunderstanding of my invention- Figure l is a perspective view of a leadpencil provided with a tip embodying my invention. Fig. 2 is an axialFig. 3 is a view of the two sheetmetal halves of the socket betweenwhich the ball of erasive material is held. Fig. 4 is a modified form ofsocket in which the two halves thereof are made in a single piece fromsheet metal-the junction of the two halves being at the shank end 'ofthe socket.

In the drawing A is the ball of rubber or erasive material; and B is thesocket proper. This socket is ofa corresponding shape to the ball, andin dimensions is slightly more than a hemisphere, so that it will closeon the ball far enough above the center line to prevent the escape ofthe latter. The ball thus is held in the socket, while at the same timeit may revolve in any direction therein. Consequently when theprotruding convex portion of the ball is rubbed upon any surface, theball will turn or move in its socket. This movement should not be toofree and unrestricted; and to this end the walls of the socket areclosed tightly enough upon the rubber ball to impede more or less, byfrictional contact, the rotary movement of the latter, without, however,arresting it entirely. When the rubber is in use, it will naturally bepressed more or less against the walls of the socket, and this will aidin checking too free rotary movement.

I am aware that heretofore it has been proposed to pivot a rubber tip ofsuitable shapewhether disk or ballso that it may revolve upon an axislike a wheel. But in such case the revolution is always in one and thesame plane, and the wear is upon one portion only of the tip. Whereas inmy tip the hell can rotate axially in every direction, and the wear canbe distributed over the whole of the surface.

The socket can be made in any suitable way. I' prefer to make it ofsheet metal in two jaw-like halves b b, from each half extending ahollow semi-cylindrical extension 6, which when fitted together, form acylindrical stem or shank adapted to be fitted and held in the sheetmetal tubular holder 0 on the end of the pencil I. In Fig. 3 such asocket is shown, made of two separate halves. In Fig. 4 the socket isrepresented as made and shaped up from a single blank of sheet metal-thetwo extremities of the semi-cylindrical shank sections b b being unitedby a cross strip b It is preferred that the divided shank b b or stem ofthe socket shall as a whole have a slight taper so that when inserted inthe holder 0 the latter will cause the two parts of the socket to closewith the desired firmness or clamping action upon the rubber ball. Thesocket as a whole may bemade removable from the holder 0, thuspermitting the rubber ball to be removed and replaced by a new onewhenever desired.

Idesire to be understood that my invention is applicable to and includesthat style of tip known as a point protector in which the sleeve orholder 0 is removable from the pencil and can be applied to either endof the same at will.

Having described my improvement and the best way now known to me ofcarrying the same into practical effect, I state in conclusion that I donot limit myself strictly to the structural details hereinbefore setforth in illustration of my invention, since the same can be varied in anumber of particulars without departure from the spirit of theinvention; but

What I claim herein as' new and desire to secure by Letters Patent is:

In a rubber tip for lead pencils, aball or sphere of erasive material,and a socket therefor of corresponding shape and size and of slightlymore than hemispherical dimensions in which the ball is held capable ofrotation, and from which a portion of it protrudes, substantially as andfor the purposes hereinbefore set forth.

In testimony whereof I afl'lx my signature in presence of two witnesses.

FRANK MCIN TYRE.

Witnesses:

SAMUEL KRAUS, OTTO YUGENBEN.

